Physical design and performance estimation of heterogeneous optical transmission systems

Abstract

This article introduces the issues of design and estimation of performance of a heterogeneous optical transmission system, taking into account the multiplicity of physical effects impairing propagation simultaneously, and, most particularly, the impact of Kerrinduced non-linear effects. We review the usual engineering tools enabling us to predict system performance, as well as design tools to optimize dispersion-management. Finally, we introduce the concept of weighted non-linear phase shifts, to capture the impact of the accumulated non-linearities on a propagating signal, and derive analytical expressions for system reach and power optimization in the context of highly heterogeneous optical link with mixed fiber features.

Performance Dependence on Channel Baud-Rate of Coherent Single-carrier WDM Systems

“…We also showed how the maximum transmission distance in dispersion unmanaged (DU) links can be inferred from the "power budget", i.e., the gap between the NLT at a given transmission distance and the linear threshold at the minimum required SNR in linear propagation 7 . Similar inferences for dispersion managed (DM) systems are well known 8 . Since the linear threshold scales linearly with R, the largest power budget (hence the longest reach) is achieved at the baud-rate that maximizes the ratioP 1 /R.…”

Nonlinear signal–noise interactions in dispersion-managed links with various modulation formats

“…They were intended to highlight with some examples the interplay between SPM and PG in various modulation formats. To get a more global view of the DM design in presence of NSNI, we next present the transmitted average power (called nonlinear threshold, NLT) that gives 1 dB of OSNR penalty at BER ¼ 10 À3 [41], and show how it changes as the symbol rate increases, both for a singlechannel and for a WDM homogeneous system. The reference DM line will again be the 20 Â 100 km SMF terrestrial system of the previous section with 30 ps/nm RDPS.…”

Fiber characteristics for next-generation ultra-long-haul transmission systems

“…A figure of merit (FOM) proposed here is based on work of [13] in order to compare several fibers where only attenuation and effective area are changed. Typically, for very long spans, attenuation will be the dominant parameters while effective area widening has the same impact whatever the span length.…”